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Humic-like substances (HULIS) are ubiquitous in the atmospheric environment, which affects both human health and climate. We present here the mass concentration and optical characteristics of HULIS isolated from aerosol samples collected in Xi'an, China. Both mass concentration and absorption coefficient (Abs 365 ) of HULIS show clear seasonal differences, with the highest average in winter (3.91 μgC m -3 and 4.78 M m -1 , respectively) and the lowest in summer (0.65 μgC m -3 and 0.55 M m -1 , respectively). The sources of HULIS_C and light absorption of HULIS were analyzed by positive matrix factorization (PMF) and four major sources were resolved, including secondary formation, biomass burning, coal burning, and vehicle emission. Our results show that secondary formation (i.e., gas-to-particle conversion from e.g., photochemical oxidation) was the major contributor to both HULIS_C (50%) and light absorption (55%) of HULIS in summer, biomass burning and coal burning were major sources of HULIS_C (~70%) and light absorption (~80%) of HULIS in winter. It is worth noting that biomass burning and coal burning had higher contribution to HULIS light absorption (47% in spring, 37% in summer, 73% in fall, and 77% in winter) than their corresponding contribution to HULIS_C concentration (41% in spring, 37% in summer, 54% in fall, and 69% in winter). However, vehicle emission had lower contribution to HULIS light absorption (26% in spring, 8% in summer, 18% in fall, and 11% in winter) than to HULIS_C concentration (24% in spring, 13% in summer, 28% in fall, and 18% in winter). These results suggest that HULIS from biomass burning and coal burning have higher light absorption ability than from vehicle emission., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Smog chamber experiments were conducted to characterize the light absorption of brown carbon (BrC) from primary and photochemically aged coal combustion emissions. Light absorption was measured by the UV-visible spectrophotometric analysis of water and methanol extracts of filter samples. The single-scattering albedo at 450 nm was 0.73 ± 0.10 for primary emissions and 0.75 ± 0.13 for aged emissions. The light absorption coefficient at 365 nm of methanol extracts was higher than that of water extracts by a factor of 10 for primary emissions and a factor of 7 for aged emissions. This suggests that the majority of BrC is water-insoluble even after aging. The mass absorption efficiency of this BrC (MAE 365 ) for primary OA (POA) was dependent on combustion conditions, with an average of 0.84 ± 0.54 m 2 g -1 , which was significantly higher than that for aged OA (0.24 ± 0.18 m 2 g -1 ). Secondary OA (SOA) dominated aged OA and the decreased MAE 365 after aging indicates that SOA is less light absorbing than POA and/or that BrC is bleached (oxidized) with aging. The estimated MAE 365 of SOA (0.14 ± 0.08 m 2 g -1 ) was much lower than that of POA. A comparison of MAE 365 of residential coal combustion with other anthropogenic sources suggests that residential coal combustion emissions are among the strongest absorbing BrC organics.

A deep transfer learning (DTL) method is proposed for the direction of arrival (DOA) estimation using a single-vector sensor. The method involves training of a convolutional neural network (CNN) with synthetic data in source domain and then adapting the source domain to target domain with available at-sea data. The CNN is fed with the cross-spectrum of acoustical pressure and particle velocity during the training process to learn DOAs of a moving surface ship. For domain adaptation, first convolutional layers of the pre-trained CNN are copied to a target CNN, and the remaining layers of the target CNN are randomly initialized and trained on at-sea data. Numerical tests and real data results suggest that the DTL yields more reliable DOA estimates than a conventional CNN, especially with interfering sources.

Secondary organic aerosol (SOA) is an important contributor to organic aerosol (OA), however, the model simulations of SOA concentrations and oxidation states remain significant uncertainties because of inadequate cognition of its formation and aging chemistry. In this study, SOA formation and evolution processes during summer in Xi'an were investigated, based on high-resolution online measurements of non-refractory PM 2.5 (NR-PM 2.5 ) species and OA source apportionment using positive matrix factorization. The results showed that the total SOA, including less oxidized-oxygenated OA (LO-OOA), more oxidized-oxygenated OA (MO-OOA), and aqueous-phase-processed oxygenated OA (aq-OOA), on average constituted 69% of OA, and 43% of NR-PM 2.5 , suggesting the high atmospheric oxidation capacity and the dominance of SOA during summer in Xi'an. Photochemical oxidation processes dominated the summertime SOA formation both during non-fog-rain days and fog-rain days, which were responsible for the formation of both LO-OOA and MO-OOA. Consistently, LO-OOA and MO-OOA in total contributed 59% to OA during non-fog-rain days and 56% to OA during fog-rain days, respectively. On the contrary, aq-OOA was mainly observed during fog-rain days, which increased dramatically from 2% of OA during non-fog-rain days to 19% of OA during fog-rain days with the mass concentration increasing accordingly from 0.3 μg m -3 to 2.5 μg m -3 . Episodic analyses further highlighted the persistently high RH period with high aerosol liquid water content (ALWC) was the driving factor of aq-OOA formation, and high O x condition could further enhance its formation. Meanwhile, air masses from east and southeast were much favorable for the formation of long-time fog-rain days, which facilitated aq-OOA production during summer in Xi'an., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Organic aerosol (OA) is a major component of fine particulate matter (PM); however, only 10%-30% of OA have been identified as individual compounds, and some are used as markers to trace the sources and formation mechanisms of OA. The temporal and spatial coverage of these OA markers nonetheless remain inadequately characterized. This study presents a year-long measurement of 92 organic markers in PM 2.5 samples collected at an urban site in Beijing from 2014 to 2015. Saccharides were the most abundant (340.1 ng m -3 ) species detected, followed by phthalic acids (283.4 ng m -3 ). In summer, high proportions (8%-24%) of phthalic acids, n-alkanes, fatty acids, and n-alcohols indicate dominant contributions of biogenic emission and atmospheric oxidation to OA in Beijing. In winter, when anthropogenic sources prevail, saccharides, polycyclic aromatic hydrocarbons, and hopanes are more prominent (4%-25%). The spatial distributions of these OA markers in China show higher concentrations in northern cities (mainly from coal combustion and biomass burning) than in southern cities (mainly from vehicular emission). The inter-annual variations of OA markers, except for hopanes, from 2001 to 2015 suggest significant alleviation of the primary OA pollution in Beijing, with an average reduction of 35%-89% compared with those before 2008. The diagnostic ratio analyses between OA markers indicate that contributions from coal combustion and biomass burning decreased, whereas those from vehicular emission increased. Increasingly large vehicle fleets have increased hopane concentrations since 2008, but the levels were 35% lower in 2015 than those in 2010-2011 because of the tightening of emission controls for vehicles. This study provides a long-term and geographical comparison (from Beijing to other locations in China and beyond) of OA markers, demonstrating the temporal and spatial variations in primary OA, and calls for more studies on secondary OA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The Guanzhong basin is a part of the three top priority regions in China's blue sky action as of 2019. Understanding the chemical composition, sources, and atmospheric process of aerosol in this region is therefore imperative for improving air quality. In this study, we present, for the first time, the seasonal variations of organic aerosol (OA) in Xi'an, the largest city in the Guanzhong basin. Biomass burning OA (BBOA) and oxidized OA (OOA) contributed >50% of OA in both autumn and winter. The average concentrations of BBOA in autumn (14.8 ± 5.1 μg m -3 ) and winter (11.6 ± 6.8 μg m -3 ) were similar. The fractional contribution of BBOA to total OA, however, decreased from 31.9% in autumn to 15.3% in winter, because of enhanced contributions from other sources in winter. The OOA fraction in OA increased largely from 20.9% in autumn to 34.9% in winter, likely due to enhanced emissions of precursors and stagnant meteorological conditions which facilitate the accumulation and secondary formation. A large increase in OOA concentration was observed during polluted days, by a factor of ~4 in autumn and ~6 in winter compared to clean days. In both seasons, OOA formation was most likely dominated by photochemical oxidation when aerosol liquid water content was <30 μg m -3 or by aqueous-phase processes when O x was <35 ppb. A higher concentration of BBOA was observed for air masses circulated within the Guanzhong basin (16.5-18.1 μg m -3 ), compared to air masses from Northwest and West (10.9-14.5 μg m -3 ). Furthermore, compared with OA fraction in non-refractory PM 1 in other regions of China, BBOA (17-19%) and coal combustion OA (10-20%) were major emission sources in the Guanzhong Basin and the BTH region, respectively, whereas OOA (10-34%) was an important source in all studied regions., Competing Interests: Declaration of competing interest We declare that the manuscript entitled “Seasonal variations in the sources of organic aerosol in Xi'an, Northwest China: the importance of biomass burning and secondary formation” is original, has not been full or partly published before, and is not currently being considered for publication elsewhere. We confirm that the manuscript has been read and approved by all named authors and that there are no other persons who satisfied the criteria for authorship but are not listed. We further confirm that the order of authors listed in the manuscript has been approved. We understand that the Corresponding Author is the sole contact for the editorial process. The corresponding author “Ru-Jin Huang” is responsible for communicating with the other authors about process, submissions of revisions, and final approval of proofs., (Copyright © 2020 Elsevier B.V. All rights reserved.)

A Gram-stain-negative, orange-colored bacterium, designated HX-22-17 T , was isolated from activated sludge of an agricultural chemical plant in Maanshan, Anhui province, China (118° 52' E 31° 68' N). The strain was strictly aerobic, non-endospore forming, non-motile, and ellipse. Growth of the strain was observed at 16-42 °C (optimum between 25 and 30 °C) at pH 6.0-9.0 (optimum at pH 7.0) and with 0-6.0% (w/v) NaCl (optimum at 1.0%). 16S rRNA gene sequence analysis showed that the strain was most closely related to Rudanella lutea KACC 12603 T (99.5% similarity). The predominant cellular fatty acids were summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c), iso-C 15:0 , and anteiso-C 15:0 . The major polar lipids included posphatidylethanolamine (PE), aminolipid (AL), and phospholipids (PL). The genomic DNA G+C content of the strain was 54.1 mol%. The ANI and dDDH values obtained between the genomes of HX-22-17 T and R. lutea KACC 12603 T were 89.3% and 39.3%, respectively. The phenotypic, chemotaxonomic, and genotypic data clearly showed that strain HX-22-17 T represents a novel species of the genus Rudanella, for which the name R. paleaurantiibacter sp. nov. is proposed. The type strain is HX-22-17 T (=KCTC 72656 T  = CCTCC AB 2019347 T ).

The chromophores responsible for light absorption in atmospheric brown carbon (BrC) are not well characterized, which hinders our understanding of BrC chemistry, the links with optical properties, and accurate model representations of BrC to global climate and atmospheric oxidative capacity. In this study, the light absorption properties and chromophore composition of three BrC fractions of different polarities were characterized for urban aerosol collected in Xi'an and Beijing in winter 2013-2014. These three BrC fractions show large differences in light absorption and chromophore composition, but the chromophores responsible for light absorption are similar in Xi'an and Beijing. Water-insoluble BrC (WI-BrC) fraction dominates the total BrC absorption at 365 nm in both Xi'an (51 ± 5%) and Beijing (62 ± 13%), followed by a humic-like fraction (HULIS-BrC) and high-polarity water-soluble BrC. The major chromophores identified in HULIS-BrC are nitrophenols and carbonyl oxygenated polycyclic aromatic hydrocarbons (OPAHs) with 2-3 aromatic rings (in total 18 species), accounting for 10% and 14% of the light absorption of HULIS-BrC at 365 nm in Xi'an and Beijing, respectively. In comparison, the major chromophores identified in WI-BrC are PAHs and OPAHs with 4-6 aromatic rings (in total 16 species), contributing 6% and 8% of the light absorption of WI-BrC at 365 nm in Xi'an and Beijing, respectively.

A bacterium, designated HX2-24  T , was isolated from activated sludge treating pesticide-manufacturing wastewater. Colonies of the strain on nutrient agar were circular, transparent, and colorless. Strain HX2-24  T shared 98.1% 16S rRNA gene sequence similarity with Extensimonas vulgaris S4 T , and less than 97% similarities with other type strains. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the strain formed a clade with E. vulgaris S4 T . The major cellular fatty acids were C 16:0 , summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c) and C 17:0 cyclo, the major polar lipids were phosphatidylethanolamine (PE), phosphatidylglycerol (PG), diphosphatidylglycerol (DPG), aminophospholipid (APL), glycophospholipid (GPL), and aminoglycolipid (AGL). The average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between HX2-24  T and E. vulgaris S4 T were 92% and 41%, respectively. The G + C content of strain HX2-24  T was 64.4 mol%. Thus, based on the phenotypic, chemotaxonomic, and genotypic characteristics, strain HX2-24  T represents a novel species in the genus Extensimonas, for which the name Extensimonas perlucida HX2-24  T sp. nov. is proposed. The type strain is HX2-24  T (= KCTC 72472  T  = CCTCC AB 2019178  T ).

To mitigate air pollution in China, a legislative 'Air Pollution Prevention and Control Action Plan' has been implemented by the Chinese government since 2013. There is, however, a lack of investigations for long-term trends in the composition, sources and evolution processes of PM 1 (particulate matter with diameter less than 1 μm) after the implementation. To evaluate the effectiveness of these control measures, we present a year-long real-time measurement of the chemical composition of PM 1 at an urban site in Beijing from November 2014 to November 2015, and the results are compared with previous studies from 2008 to 2013 to gain insights into the variations of the chemical composition and sources of PM 1 in Beijing. Large seasonal differences were observed in the mass concentrations of PM 1 species and general declining trend was observed in the last seven years. Specifically, the annual averages of mass concentrations in 2014-2015 decrease by 16-43% (PM 1 ), 23-43% (organic aerosol, OA), 38-68% (sulfate), 26-51% (nitrate), 18-33% (ammonium) and 27-38% (chloride) compared to those from 2008 to 2013. During winter and summer, the seasonal mass concentrations of sulfate and nitrate show more significant declines especially in summer 2008 (79% and 81%) and summer 2011 (76% and 77%). The nitrate-to-sulfate ratio is higher in 2014-2015 (1.5 ± 0.6) than that in 2013 (1.0 ± 0.3), largely due to significant reduction in SO 2 emissions, suggesting that nitrate is becoming more important than sulfate in particulate pollution in Beijing. OA is the dominant PM 1 fraction (>45%) in all seasons and the mass concentrations/contributions of both primary and secondary OA show different seasonality. As for the more oxidized oxygenated OA (MO-OOA) and less oxidized oxygenated OA (LO-OOA), the contributions of MO-OOA are much higher than those of LO-OOA (27-62% vs. 6-26%) in both high-pollution and low-pollution days. Aqueous-phase processes are found to facilitate the formation of MO-OOA while photochemical oxidation formation is a major contributor of LO-OOA in winter, and photochemical oxidation plays a major role in the formation of MO-OOA in summer and fall. The current study provides a comprehensive seasonal comparison of chemical composition and formation of PM 1 in Beijing and a pacesetter in tackling PM pollution for other equally polluted megacities, after implementation of more stringent control measures after 2013., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Sulfate and nitrate from secondary reactions remain as the most abundant inorganic species in atmospheric particle matter (PM). Their formation is initiated by oxidation (either in gas phase or particle phase), followed by neutralization reaction primarily by NH 3 , or by other alkaline species such as alkaline metal ions if available. The different roles of NH 3 and metal ions in neutralizing H 2 SO 4 or HNO 3 , however, are seldom investigated. Here we conducted semi-continuous measurements of SO 4 2- , NO 3 - , NH 4 + , and their gaseous precursors, as well as alkaline metal ions (Na + , K + , Ca 2+ , and Mg 2+ ) in wintertime Beijing. Analysis of aerosol acidity (estimated from a thermodynamic model) indicated that preferable sulfate formation was related to low pH conditions, while high pH conditions promote nitrate formation. Data in different mass fraction ranges of alkaline metal ions showed that in some ranges the role of NH 3 was replaced by alkaline metal ions in the neutralization reaction of H 2 SO 4 and HNO 3 to form particulate SO 4 2- and NO 3 - . The relationships between mass fractions of SO 4 2- and NO 3 - in those ranges of different alkaline metal ion content also suggested that alkaline metal ions participate in the competing neutralization reaction of sulfate and nitrate. The implication of the current study is that in some regions the chemistry to incorporate sulfur and nitrogen into particle phase might be largely affected by desert/fugitive dust and sea salt, besides NH 3 . This implication is particularly relevant in coastal China and those areas with strong influence of dust storm in the North China Plain (NCP), both of which host a number of megacities with deteriorating air quality., Competing Interests: Declaration of competing interest The authors declare no competing financial interest., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Topramezone is a 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitor. Due to its broad-spectrum, high efficiency, and low toxicity, topramezone is a candidate herbicide for the construction of genetically modified (GM) herbicide-resistant crops. In the present study, we screened a topramezone-resistant isolate Sphingobium sp. TPM-19 and cloned a topramezone-resistant HPPD gene ( SphppD ) from this isolate. Sp HPPD shared the highest similarity (53%) with an HPPD from Vibrio vulnificus CMCP6. Sp HPPD was synthesized in Escherichia coli BL21(DE3) and purified to homogeneity using Co 2+ -affinity chromatography. Sp HPPD was found to be a monomer. The K m and k cat of Sp HPPD for 4-hydroxyphenylpyruvate (4-HPP) were 82.8 μM and 15.0 s -1 , respectively. Sp HPPD showed high resistance to topramezone with half maximal inhibitory concentration (IC 50 ) and K i values of 5.2 and 2.5 μM, respectively. Additionally, Sp HPPD also showed high resistance to isoxaflutole (DKN) (IC 50 : 8.7 μM; K i : 6.0 μM) and mesotrione (IC 50 : 4.2 μM; K i : 1.3 μM) and moderate resistance to tembotrione (IC 50 : 2.5 μM; K i : 1.0 μM). The introduction of the SphppD gene into Arabidopsis thaliana enhanced obvious resistance against topramezone. In conclusion, this study provides a novel topramezone-resistant HPPD gene for the genetic engineering of GM herbicide-resistant crops.

Two-component systems (TCSs) are highly conserved in prokaryotes, endowing cells with multiple physiological functions to respond to changes in the ambient environment. The signaling pathway of a typical TCS consists of a sensory histidine kinase and a response regulator. The TCSs of Kocuria rhizophila, which is usually used as a target strain for various antibiotics and other adverse factors, have captured our interest due to their potential roles in bacterial adaptation for survival. Herein, the distribution and putative biological functions of the TCSs of K. rhizophila DC2201 were analyzed by using bioinformatics, and a preliminary TCS regulatory network was constructed. A representative and important TCS (i.e., HK8700-RR8701 system), which is homologous to the LiaS-LiaR system previously discovered in Bacillus subtilis, was identified and characterized through yeast two-hybrid screening and phosphorylation assays. Detailed information of TCSs is expected to offer novel insights into the adaptation mechanism of K. rhizophila and thus boost its application.

In this study, a bacterial strain P13 capable of degrading pendimethalin was isolated from the soil of a fruit garden. Based on observed cellular morphology and physiology characteristics and a phylogenetic analysis of 16S rRNA gene sequences, strain P13 was identified as a member of the genus Paracoccus. Strain P13 grew on pendimethalin as the sole carbon source, and could degrade 100 mg/L pendimethalin within 2 days and 200 mg/L pendimethalin within 5 days. Pendimethalin degradation was proposed to be initiated by oxidation ring cleavage to yield 1,3-dinitro-2-(pentan-3-ylamino)butane-1,4-diol, an alkane organic compound that was identified by ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS), which then underwent a series of enzymatic reactions to produce CO 2 and H 2 O. The optimal pH and temperature for pendimethalin degradation by strain P13 were 7.0 and 30 °C, respectively. This study identified the bacterial strain Paracoccus sp. P13, which degraded pendimethalin with a relatively high efficiency, and presents a previously unreported microbial pendimethalin degradation pathway.

Objectives: To characterize a novel dimethoate amidohydrolase from Sphingomonas sp. DC-6., Results: A gene, dmhA, encoding the dimethoate amidohydrolase responsible for transforming dimethoate to dimethoate carboxylic acid and methylamine, was cloned from Sphingomonas sp. DC-6. Sequence analysis and molecular modeling indicate that DmhA shares 31-57 % amino acid sequence identities with other functionally confirmed amidohydrolase. DmhA was expressed in Escherichia coli BL21 (DE3) and purified by Ni-NTA affinity chromatography. The purified DmhA could hydrolyze 4-acetaminophenol, dimethoate and propanil. DmhA activity was optimal at 30 °C and pH 7.5. Hg(2+), Zn(2+), Cu(2+), Cd(2+), Tween 80, Triton X-100 or SDS strongly inhibited its activity. The K m and k cat values of DmhA for dimethoate are 0.02 mM and 1.2 s(-1), respectively., Conclusions: DmhA was confirmed to be a novel dimethoate amidohydrolase which could eliminate the toxicity of dimethoate, providing a novel gene resource for the development of pesticide-degrading enzyme preparation and mechanistic study of dimethoate hydrolysis.

Objective: To prepare the aortic extracellular matrix (ECM) scaffold by using different methods to decellularize porcine ascending aorta and to comprehensively compare the efficiency of decellularization and the damage of ECM, evaluation of biomechanical property and biocompatibility., Methods: Thirty specimens of fresh porcine ascending aorta were randomly divided into 6 groups (n=5). The porcine ascending aorta was decellularized by 5 different protocols in groups A-E: 0.1% trypsin/0.02% ethylenediamine tetraacetic acid (EDTA)/PBS was used in group A, 1%Triton X-100/0.02% EDTA/ distilled water in group B, 1% sodium deoxycholic acid/distilled water in group C, 0.5% sodium deoxycholic acid/0.5% sodium dodecyl sulfate/distilled water in group D, and 1% deoxycholic acid/distilled water in group E; and the porcine ascending aorta was not decellularized as control in group F. The ascending aorta scaffolds were investigated by gross examination, HE staining, DNA quantitative analysis, immunohistochemistry, and scanning electron microscopy were used to observe the efficiency of decellularization, microstructure of the ECM, the damage of collagen type I and elastin, the structure of intimal surface, and biomechanical property. The 90 Sprague Dawley rats were randomly divided into 6 groups (n=15). Each scaffold was implanted in the abdominal muscles of rats respectively to evaluate the immunogenicity and biocompatibility., Results: HE staining and quantitative analysis of DNA showed that the cells were completely removed only in groups A and D. The expression of collagen type I in group A was significantly lower than that in the other 5 groups (P < 0.05), and serious damage of the basement membrane and decreased beomechanical property were observed. The maximum stress and tensile strength in group A was significantly lower than those in the other groups (P < 0.05), and elongation at break was significantly higher than that in the other groups (P < 0.05). The destruction of collagen type I was significant (P < 0.05) in group D, but the basement membrane was integrity, the biomechanical properties were close to the natural blood vessels (group F) (P > 0.05). Implantation results showed that the scaffold of group D had superior immunogenicity and histocompatibility to the scaffold of the other groups. The inflammatory reaction was gentle and the number of the inflammatory cell infiltration was lower in group D than in other groups (P < 0.05)., Conclusion: It is concludes that 0.5% sodium deoxycholic acid/0.5% sodium dodecyl sulfate/distilled water is more suitable for the decellularization of porcine aorta, by which the acquired ECM scaffold has the potential for constructing tissue engineered vessel.

The taxonomic status of a moderately halophilic bacterium, strain N4(T), isolated from soil of a chicken farm in China was determined. It was Gram-negative, non-spore-forming, motile, and rod-shaped. Phylogenetic analysis based on 16S rRNA gene sequence indicated that this strain belonged to the genus Salinicola, as it showed the highest sequence similarities to Salinicola salaries M27(T) (98.3 %), Salinicola socius SMB35(T) (98.1 %), and Salinicola halophilus CG4.1(T) (98.1 %). The major cellular fatty acids were C(16:0) (25.6 %), C(18:1)ω7c (35.0 %), and C(19:0) cyclo ω8c (11.9 %), which are properties shared by members of the genus Salinicola. The DNA G+C content of strain N4(T) was 69.1 mol %. The level of DNA-DNA relatedness between strain N4(T) and the other three type strains of the genus of Salinicola salaries M27(T), Salinicola socius SMB35(T), and Salinicola halophilus CG4.1(T) were 34.3, 28.7, and 26.9 %, respectively. Based on the results of phenotypic, chemotaxonomic, DNA-DNA relatedness, and phylogenetic analysis, strain N4(T) should be classified as a novel species of the genus Salinicola, for which the name Salinicola zeshunii sp. nov. is proposed, with strain N4(T) (=KACC 16602(T) = CCTCC AB 2012912(T)) as the type strain.

A bacterial strain P2 capable of degrading 3,5,6-trichloro-2-pyridinol (TCP) was isolated and characterized. Phylogenetic analysis based on 16S rRNA gene sequence indicated that it belonged to the genus of Cupriavidus, because it showed the highest sequence similarity to Cupriavidus pauculus LMG 3413(T) (99.7 %) and DNA-DNA relatedness value between strain P2 and C. pauculus LMG 3413(T) was 76.8 %. In combination with morphological, physiological and biochemical characters, strain P2 was identified as C. pauculus. It could use TCP as the sole carbon source and energy source for its growth. It showed a high average degradation rate of 10 mg/L h in mineral salt medium amended with TCP (50-800 mg/L). During TCP degradation, chloridion was released into the medium in two obvious discontinuous stages. Along with this, two colorful metabolites were produced. Finally, the molarity of the total released chloridion was three times that of the initial TCP in the medium. This is the first report of TCP-degrading strain from the genus of Cupriavidus and the detection of two colorful metabolites during TCP degradation. Strain P2 might be a promising candidate for its application in the bioremediation of TCP-polluted environments.